For the BrF3 Lewis structure, calculate the total number of valence electrons for the BrF3 molecule. There are a total of 28 valence electrons for the BrF3 Lewis structure. After determining how many valence electrons there are in BrF3, place them around the central atom to complete the octet.
Bromine is the least electronegative atom in the BrF3 Lewis structure and therefore goes at the center of the structure